DENVER -- Pitchers Gonzalez Germen and Aaron Laffey made their debuts for the Colorado Rockies on Friday and played key roles in their 5-3 win over the Atlanta Braves.

Three days after the Rockies claimed him off waivers from the Chicago Cubs, Germen made his first major-league start and pitched three scoreless innings. Laffey followed him to the mound and worked 2 1/3 innings, giving up a three-run homer to the next-to-last batter he faced that trimmed the Rockies' lead to 5-3.

"Those are huge innings for us, especially with how taxed our 'pen has been," catcher Nick Hundley said. "To get 5 2/3 (innings) out of those guys and have the lead -- you got to tip your hat to both of them."

The Rockies had to call up pitching reinforcements in the wake of a lengthy rain delay Thursday that saw starter Kyle Kendrick leave after one inning, David Hale depart with a groin injury and manager Walt Weiss use all but one of his eight relievers.

Germen, who last started a game at the Double-A level in the New York Mets' organization on Sept. 3, 2012, gave up a leadoff single to second baseman Jace Peterson in the first but got center fielder Cameron Maybin to ground into a double play. The only other baserunner Germen allowed came with two outs in the fourth when he walked pitcher Shelby Miller. Germen got Peterson to pop out and left after a 34-pitch outing that included 22 strikes.

"He pounded the strike zone," Hundley said. "Was on the edges with his fastball. Threw the changeup whenever he wanted to. Warming up, I was like, 'This guy's lights out.' And he carried it over to the game."

Miller, the Braves' lone All-Star, gave up a career-high 11 hits and a season-high five earned runs in five innings as he lost his fourth consecutive game, which is a career-high.

"This is the worst my fastball command has been all year. It's not even close," Miller said. "My ratio of good fastballs was 50-50. I probably threw more balls with my fastball. I didn't get ahead in the count. Just left balls over the middle of the plate. Everything was up. Just a terrible day."

Laffey, who won for the first time in the majors since Sept. 25, 2012, with Toronto, worked a scoreless fourth and fifth but gave up a three-run homer to first baseman Kelly Johnson with one out in the sixth.

"It was a cutter that stayed side-to-side," Laffey said.

Third baseman Chris Johnson followed with a single, chasing Laffey. He was replaced by LaTroy Hawkins, who grabbed catcher A.J. Pierzynski's hard comebacker and started an inning-ending double play.

When the Rockies got the game to Hawkins, who worked 1 2/3 innings, they were in familiar territory with relievers back in their accustomed roles. And that wouldn't have happened without the work of Germen and Laffey.

"German was really impressive," Weiss said. "He showed a good fastball and a very good changeup. Him getting through three (innings) was big for us. It shortened the game. He hadn't made a start in a few years, a little bit of uncharted territory."

Closer John Axford retired the side in order in the ninth to earn his 16th save in 17 opportunities.

Right fielder Carlos Gonzalez put the Rockies ahead 5-0 when he led off the fifth against Miller (5-5) with his 12th homer. He lined a first-pitch fastball on the outer portion of the plate over the wall in center.

"It was away, one of those Cargo reach (swings)," Gonzalez said. "When things go good, I can cover far away, so I was able to put the barrel to the ball and drive it to center field."

The scoring began in the first when third baseman Nolan Arenado doubled home a run, snapping a career-high-tying streak of nine games without an RBI.

Shortstop Daniel Descalso ended a career-high stretch of 20 hitless at-bats when he tripled home a run in the three-run fourth and scored on left fielder Brandon Barnes' single.

The Rockies made it 4-0 when center fielder Charlie Blackmon tripled and scored on second baseman DJ LeMahieu's ground-rule double.

NOTES: Braves CF Cameron Maybin singled in the sixth to extend his hitting streak to a career-high-tying 10 games. ...Rockies RHP David Hale (left groin strain) was placed on the 15-day disabled list. He was injured pushing off from third and scoring on a sacrifice fly Thursday. ... Rockies LHP Aaron Laffey had his contract selected from Albuquerque, where he was 2-3 with a 4.91 ERA in 19 games and five starts. To make room for Laffey on the 40-man roster, LHP Tyler Anderson was recalled and placed on the 60-day disabled list. He hasn't pitched this season because of his second stress fracture in his left elbow. ... Rockies RHP Scott Oberg was optioned to Albuquerque...Rockies SS Troy Tulowitzki was given a planned day off. ... Braves LHP Josh Outman (thoracic outlet syndrome) began a rehab assignment with the rookie-level Gulf Coast League Braves and pitched one scoreless inning. ... The Braves got eight innings from their bullpen Thursday after starter Alex Wood threw two pitches and didn't return after a two-hour, six-minute rain delay. It was the longest Atlanta's bullpen has gone since also throwing eight innings on Sept. 20, 2014, against the New York Mets. Braves relievers allowed 16 hits on Thursday, the most by the Atlanta bullpen since Aug. 22, 2008, when St. Louis had 21 hits.